<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" href="./css/bootstrap.css">
</head>
<body>
    <div class="container border mt-4">
       <div class="row">
           <div class="col-4 border">
               column
           </div>
           <div class="col-6 border">
            column
        </div>
        <div class="col-2 border">
            column
        </div>
       </div>
    </div>

    <div class="container border mt-4">
        <div class="row">
            <div class="col-4 col-md-8">
                内容
            </div>
        </div>
    </div>
    
</body>
</html>